Roller Chain Sprocket, Type B, Stock Bore, #40 Chain, 1/4 in-20 Screw, Steel, 1/2 in Pitch

B Style sprockets are flat sprockets with a hub extension on one side. These plain bore sprockets can easily be bored to a metric or standard size to fit your application. Keyways, set screws and hardened teeth are quick alterations that can be made.